. 1'88 G.R.B.

Organic Chemistry (or Competitions

OBJECTIVE OUESTIONS ~iii.Ii,.iii

Set I: This set contains questions .with single correct answer. (a) 5 0 (b) 4 0
1. C()mpounds having same number and kind of atoms but (c) 3 0 (d) 2 0
different arrangement ofatoms in their molecules are called: 12. Keto-enol tautomerism is not observed in :
(a) allotropes 0 (b) isotopes 0 [JEE (WB) 201(il
(c) isomers 0 (d) polymers 0 (a) C6HsCOC6HS 0 (b) C6H s COCH=CH2 0
2. Isomers have essentially identical: (c) C 6H sCOCH2COCH3 D (d) CH3COCH2COCH3 0
(a) structural formula 0 (b) chemical properties 0
13. Isomerism in aIkynes is:
(c) molecular formula 0 (d) physical properties 0
(a) functional 0 (b) ()ptical 0
3. Whicbofthe following has asymmetric carbon atom?
[BHU (Med.) 2007]
(c) geometrical o (d) conformational 0
14. The type of is()merism observed in urea molecule is:
(a) CH2CI-CH2 Br 0
(b) CH3CHDCI 0 (a) chain 0 (b) position 0
(c) CH3CHCl 2 0 (c) tautomerism 0 (d) none of these 0
(d) CH2Br-CHOH-CH3 0 15. Which of the following is not an isomer ofbut-l-yne?
4. Total number of isomeric alcohols with formula C4 H lO O is: (a) But-2-yne 0 (b) But-I,3-diene 0
(a) I 0 (b) 2 0 (c) But-2-ene 0 (d) Methyl cycl()propene 0
16. Number of is()mers of molecular formula ~ H2 Br2 is:
(c) 3 0 (d) 4 .0
5. Number of acyclic isomers represented by molecular (a) 1 0 (b) 2 0
formula C 4 H IO Ois: [PMT (MP) 2006; AFMC 2010] (c) 3 0 (d)4 0
(a) 7 0 (b) 6 0 17. C 7 H s O sh()w8 h()w many isomers?
(c) 4 0 (d) 5 0 (a) 2 0 (b) 3 0
[Hint: 4 alcohols and 3 ethers,

c
0 (d) 5 0
. . CH 25) (c) 4

[ 6 "' 6c",; 6;
OH OH OH
Alcohols: CH 3CH:zCH2CHPH, . CHOH,
H3C
H3C~T
/"nCH20H, (CH3)3 COH
Hint: "- I ;
H3C . "~1; CH3

< 6" 6']

CH3
Ethers: CHPC3H7 , CiH5OC2H5, CH 30CH ]
. CH3
6. The compound C 4 H lO O can show: [JIPMER 2005]
(a) metamerism 0 (b) position isomerism 0
(c) functional isomerism 0 (d) all of the three 0 18. CH3CH 2 0Hand CH3~H3 are the examples of:
7~ The molecular formula of a saturated compound is [CET (Karnataka) 2008; UPSEE (Engg.) 20081
C 2H 4 C1 2 • This formula permits the existence of two: (a) functional isomerism 0 (b) chain isomerism 0
(a) functional isomers 0 (b) position isomers 0 (c) metamerism 0 (d) poSition isomerism 0
(c) optical isomers 0 (d) cis-trans isomers 0 19. The compound which forms only one monochloro product
8. Th\: compound which is not isomeric with diethyl etheris: when treated with chlorine is:
(a) 'methyl n-propyl ether 0 (b) I-butanol 0 (a) n-pentane 0 (b) isopentane 0
(c) 2-methyl propan-2-0ID (d) butanone 0 _ (c) neo-pentane 0 (d) none·ofthese 0
9. Which type of isomerism is shown by diethyl ether and 20. Stereoisomers have different: [JIPMER 20081
methyl propyl ether? (a) molecular formula 0 (b) structural formula 0
(a) Chain 0 (b) Functional 0 (c) configutJltion 0 (d) conformation . 0
21. Select the pair of compounds which exhibit cis-trans
(c) Metamerism 0 (d) Position 0
(geometrical) isomerism:
10. Aldehydes and ketones are:
(a) fumaric acid and maleic acid 0
(a) homologues 0 (b) isomers 0 (b) malonic acid and succinic acid 0
(c) allotropes 0 (d) polymers 0 (c) lactic acid and tartaric acid 0
II. Maximum number of isomers for an alkene with molecular
(d) acetic acid and ~tonic acid 0
formula, C4 Hg is:
Isomerism 1i~~?i~~
" 'if"!)
22. The isomerism that arises due to restricted bond rotation is : 34. The number of pOsSiblealkynes with molecular formula
[PET (Kerala) 1010) CsHs is: ,
(a) optical isomerism 0 (b) metamerism 0 (a) 2 '0 (b) 3 o
(c) position isomerism 0 (d) functional isomerism 0 (c) 4 0 (d) 5 o
(e) geometrical isomerism '0 35. Glucose has how m~y optical isomers?
13. Which of the following will have least hindered rotation (a) 8 0 (b) 12 0
about carbon-carbon bond? (c) '16 0 (d) Cannot be predicted 0
(a) Ethane 0 (b) Ethylene 0 36. Which of the following compounds can exhibit both
(c) Acetylene, 0 (d) Hexachloroethane 0 geometrical isomerism and enantiomerism?
14. A compound contains two dissimilar asymmetric carbon ' (a) CH3CHQHC2H s o
'atoms. The number of stereoisomers is: [DPMT 1006) (b) CH3 CHOHCOOH o
(a) 2 0 (b) 3 0
(c) 4 0 (d) 1 0 o
15. Isomers which ~ be interconverted through' rotation
around a single bond are:
(a) position isomers 0 (b) enantiomers 0 (d) All of the above 0
(c) metamers 0 (d) conformers 0 37. During debromination of meso dibromobutane, the ,major
16. Meso tartaric acid and d-tartaric acid are: compound formed is:
(a) position isomers 0 (b) .racemic mixture 0 (a) n-butane 0 (b) I-butene 0
(c) enantiomers 0 (d) diastereomers 0 (c) trans-2-butene 0 (d) cis-2-butene 0
17. The number of conformations Of ethane is: 38. The most stable conformation of ethane is:
(a) 1 0 (b) 2 0 (a) boat forin 0 (b) chair form 0
(c) 3 0 (d) infinite 0 (c). eclipsed form 0 (d) staggered form i 0
18. Out of the following, the alkene that ,exhibits optical 39. At room temperature the eclipsed and the staggered forms
isomerism is : [AIEEE 2010) of ethane cannot be isolated because:
(a) 2-methyl-2-pentene 0 (b) 3-methyl-2-peotene 0 (a) both the conformers are equally stable, ' 0
(c) 4-methyl-l-penteneD (d) 3-methyl-I-pentene 0 (b) they interconvert rapidly 0
29. Chiral molecules are ,those which are: (c) there'is a large energy bamer of rotation about the
(a) superimposable on their mirror image 0 a-bond 0
(b) not superimposable on their mirror image 0 (d) the energy difference between the conformers is large
(c) unstable molecules 0 []
(d) capable of showing geometrical isomerism 0 40. The number of geometrical isomers in the' following
30. The method of separation of d- and I-isomers from the compound'CH3-CH=CH-CH-CH--,-C2H5 is:,
racemic mixture is called: (a) 4 0 (b) 3 ' 0
(a) resolution 0 (b) dehydration 0 (c) 2 0 (d) 5 • D.
(c) asymmetric synthesis 0 (d) Walden inversion 0 41. Tartaric acid molecule contains two asymmetric carbon
31. Mesotartaric acid is optically inactive due to presence of: atoms. The number of optical isomers of tartaric acid is:
(a) molecular symmetry 0 (a) 2 0 (b) 3 0
(b) molecular asymmetry 0 (c) 4 0 (d) 5 0
(c) external compensation 0 41. Lactic acid shows optical activity in:
(d) two asymmetric carbon atoms 0 (a) solution 0 (b) liquid state D-
32. Two geometrical isomers are given by which of the (c) crystalline state 0 (d) all of these O
following compounds? 43. Enantiomers can be better separated by:
(a) Ethylidene dibromide 0 (a) salt formation method b
(b) Acetylene tetrachloride 0 (b) mechanical separation o
(c) Acetylene tetrabromide 0 (c) fractional crystallisation o
(d) Acetylene dibromide 0 (d) fractional-distillation,'~ o
33. Which one is the correct statement? 44. Which, of the f~llowiIig wi11~xbibit chirality? '
(a) (+) tartaric add and mesotartaric acid are tautomers 0
(a) Neopentane tJ.·-:-(b) Isopentane d
(b) (+) tartaric acid and mesotartaric 'acid are diastereo- (c) 3-Methylhexane i
t:r (d) 2-M~ylhexane 0
isomers 0 45. Which of the following will not show cis-trans isomerism?
(c) (+)tartaric acid and (-) tartaric acid are diastereo- (a) CH3-C=CH~CH2- '-:::CIl;:,.- 0
isomers 0
I : 3,
CH 3
, , (d) (+)tartaric acid and mesotartaric acid are enantiomers
o
 - '

~.R:B.'organir: Che11iistryjorCompetitions
(b) CH 3-CH-CH CH-CH2---"CH
, t ' ," , 3 ,
o (a) 4 ' 0 , (b) 3 o
'
CH
3 " ' (c) 2 ,,' 0 (d) 5 ' o
, ' \ 56. Consider the following Qrganic compound;
" ·'~·(ct,CH~:-CH.=CH-dH3, 0 CH3-CH2-'-CH2-CH2-CH2-CH2-CH3
I ,21 4 S 67
" (d) CH3-CH2-CH , CH-CHi-CH~ 0
• '46. How many primary, ai'nines are possible for the formula ,To make ita chiral compound, the attack should be on
carbon : ' ' " (DeE 2001)
C 4 Hll N? ,
(a}.l 0 (b) 2 0, (a) I 0 (b) 3 0
, " (c) 3 ' ,". 0 (d}A ' ' ",.,' 0 (c) 4 ',," ,0 (d) 7 0
47• How many optlcaliy ,active stereoi'somers are possible for 57. A compound withmolecula:r formula C 7 H16 shows optical
, butane-2,3,.diol? ' isomerism, the ,compound will be : [eBSE (Med.) 2001]
(a) 1 ' .' 0 (b) 2 ' 0 (a) 2, 3-dimethyl pentane 0
(c) 3 . 0, (d) 4 , \ ' 0 (b) 2, 2-dimethyl pentane 0
48., The number of' possible enantiomeric pairs ~at ,can be (c) 2~methylhe~ane 0
" ' produced during,monochlorinationof 2-methyl butane is: ' (d) none of the abOve 0
(a) 2
, (c) 4
0 (b) 3
0 (d) I
,.49. Tautomerism will be expla~ed by:
'(~) (CH3hNH ' CJ, (b) (CH 3h CNO
0
0
0
·58. M.;xrtH
, H ,,'
(c)R 3CNt>z 0 (d) RCH2NOi O. Hydrogenation of the above compound in the presence of
, 50. ". 4n'enantiomerically pure acid is treated with racemic \ \ poisoned palladium catalyst gives: ,'(lIT (S) 2001)
.~ ,. - .
(a) optically active compound 0
nuxture of an alcohol haVing one chiral' carbon. The ester \
fomiedwiU~e: ,', (lIT 2003) \ (b) an optically inactive compound 0
(a) optically active mixture 0 " (c) a racemic mixture 0
(b) pure enantiomer ' , 0 (d) a diastereomeric mixture" 0
, (c) meso compound 0 59. The number of isomers for the compound with molecular
formula.C4;arC~I is: (PET (Kerala) 2007)
',,(g), r~cemic'tnixture ' " 0
51.~-Methylpenta-2,3-diemds aehiral because it haS: '
(a) 3 0 (b) 4 0
(a) a plane of sytrnnetry , 0 (c) 5 0 (d) 6 0
(6) a centre of symmetry 0 (e) 7 0
60. The tWo compounds shown 'in figure l:!elow are:'
(c) a c; axis of symmetry 0
" ,(d),bothiplane and a centre ofs~etry, 0
'52. 'The racemizationofopiicalJy acti:ve compounds is driven and
'by:,"""
" ,.,:(a), ellth~lpy, , o
(b) entropy . 0
" (c)"¢nthalpy andentiopy 0 (d) element of symmetry []
'53. ,The follow,~rig cOIllPound can show: l a)
diastereomers 0 (b) enantiomers o
. SIh)c C(H ,H (c) epimers 0 (d) regiomers o
61. The compounds given below are :
CH3' )c(·,
, ' " CI:h' , eOOH
(a) opticalisomerism ' 0
HO-@--COOH ~d HO--@-COOH,

(b) geometrical isomerism 0 (a) enantiomers ' 0 (b) identical 0

(c) optica~andgeometricaUsonierism 0 (c) regiomers 0 (d) diastereomers 0
(d) tautomerism 0
62. Which of the following compounds will exhibit geometrical,
,.:54. The optically active tartaric acid is named as D-(+)-tartariciSl)merism?' ,.' (lIT (S) 2000)
'acid~eca~e it -has a positive: (a) I~Phenyl-2-butene 0
" (a) opticaFr0t;ationand is: derived from D-glucose 0, ,(bY 3~Phenyl-l~butene 0
•(b) pH ino~ganic sOlvent o (c) 2-Phenyl-l-butene , 0
, , (c):optical' rotation and is derived from '
, " .D-(+) r-klyceraldehyde" , " " " 0
(d) l,l-Diphenyi-I-propene 0
63. Which of t~e ~ollowing 'doe~ not show geometrical
: (d}opticaf rotation only when substituted by deuterium 0 . isomerism? ,(A,IEEE2002)
55. kIo~man)' cyclic isomers ofCsHIO are possible? . .(a) l,2-Dichloro~l-pen.ten~" 0
[DPMT 2000)" " (b) 1,3-Dic::hlQro~2-pe~fene 0
lsamerism
., .

(c) I-Dichloro-l~pentene D . (a) 2-ChlQrobutane . ,JJ '>'.

(d) 1,4-Dichloro-2-pentene 0 . (b)2,3-Dichlorobutane' '."
· · .• ,0
o
64. A'similarity between optical and geometrical isomerism is . (c) 2,3:-Dichloropentane
tJ
h
i," ."
that: . '... '.,' [AIEEE2002] , (d) ,2-Hydroxypropanoic acid
(a) each forms equal number of isom~rs for·.~, given C1l3
compound ," . " .0 70.,. . . ~ [F]. -,B.-:.r~:--,C_4:.,...
(b) if in a compOund one is present then So is th~'l>therO '. H 20
(c) both are included in stereoisomerism' .'. 0 H3 C ' . O H , 5 such products
(d) they have no similarity , ,0, are. possible
65. Which of the followirig hydrocaibonshas lowest dipole, How many structures of[F] is possible? . (lIT (S) 2003]
moment?'
"('a') C.H.'.

'. .H
3'),
,C' ··. C· <.
,.,.' ",
CH

'. '. H
3
. ,(IIT(S}2(f()21"
' . .
(a) 2 .'
.' (c) 6 ' '. .
0 (b) 5 '
0 (d) 3 '.
,J]" , . 71. On~onoch1orination: 2-methylbutane, th.e total nmnb.f;ir, .'
of chiral compounds 1S:
of
. "
"0
.0 .
(IlT(S} 1~041: "..
(b) CHi-C==C-:CH3 0 (a) 2: '; " o
(b) 4 .. . <'[1 '
. • ,(c) 6 , · . ,0 (d) ,8', . '.<0
(c)CH 3- CH:i;"':"'C C-H 0 12•.... Which type ofisomerismis shown by 2,3~dichlor6butane? .
(d) cH .' Ca~cS='CH ' ' ' ,D ,",' ' [AI£EE100S] ..
2
66•. Among the folloWing four ,structures I ,to IV: (a) D i a s t e r e o O (b) Geometrical 0,
.

,y, fH ' 0 (d) Struc;tuiaL' . ; 0

/ " '.

fH3' 3
(c) Optical
'.73. Correct configuration of the following is:' [ADMS200s)
C2 Hs--'-CH-C 3 H7 , CH3',--C--;-CH-C2Hs
(I) , (II),:: .
'H+OH
. H .
1"
·.·CH3
I,
CH 3 TH OH

'H-c-f' C2Hs~~~-C2Hs
(a) lS,2S 0 (b) 1S,2R
.
0
'. H (c) lR,2S 0 (d) lR,2R 0
. (III) (AIEEE2003)
74. Which of the following is optically active? (BHU 2005).. ,.'~
(a) all four are chiral compounds' . ·0 (a) Butane 0 (b) 4-Methylheptane 0
(b) only (I) and (II) are chii'alconipounds . 0 (c) 3-Methyl heptane 0 (d) 2-Methyl heQtane 0 '
(c) only (III) is a chiral compound 0 75. Maximum enol content is in: (nCE 2005; AIIMS 2008)
(d) only,(II) .and (IV) are chifal compounds 0 0 0 0
67. '~ich~of the following is most . likely to· show optical ';
.' Isomensm? . . " [UPSE~TZ004] (a)A 0 (b»)~.D
....... •. H'.. •..... . . · H · .... .

(C)~H O(d)~i~
. '.' . 1 " .. 1 '
. (a)HC==C-f~C==CH 0 (b) HC==C-f-CH3 0
CI .. CI'
eOOH ..COOMe.'..: ! ..

H CI

(c) HC==C-r-H
1
o (d) HC=C-C=CH2
1
o 76.. :+=~: :~4=;.,
COOMe"COOH~i'; ,,'
Cl (I) . (II}" .... '. t' i,,'

68. The molecular formula of diphenylmethane, Structures (I) and (II) are: , '., ' :f~PMr200S] .
(a)enantiomers 0 (b)diaSter.eomei's· . . D. .
(c) meso compounds 0 (dfid~iicrtl:'" ',' .', 0 '
77. The two structures of D-glucopyranose forms are: ' . ,
. • . . [UT(S) 2005]
How many structural isomers are possible when one of the
hydrogen is replaced by a chlorine atom?
(a) anomers o (b) enantiomers D'
. [CBSE (Med.) 2004] (c) epimers, . 0 ,(d) diastereoisomers' ,- []
. ~. Which of the following will show~,!!.metricaliSOinerism
.. ?
(a) 6 0 (b) 4 0 '. . LJK,:ECE (Med.)200S} :
(c) 8 0 (d) 7 0 (a) C 2 H s B r , O (b) CH2 (COOHh'" .'[j.
69. Which one of the follQwingwill have a meso-isomer also?
, .' . (AlEEE 2004; JCECE (Med.) 200S) (c) (CH)i(COOHh 0 ,(d)O:2H6 ......:',: ,,'p
....
., :
.
- " .
 G.R.B. Organic Chemistry/or Competitions

79•.Whichof the following compounds is expected to b~

optically active? [CET (Karnataka) 2006; AFMC 2008]
(a) (CH3h CHCHO o
(b) CH3 CH2CH 2CHO 0
(c)-< {i~3CiI2CH(Br)CHOD . (d) CH3CH2CBr2CHO 0
.80•. T~e n~ber of optical isomers of. .
,r.:; . . . . Cf!~CH(OH)CH(OH)CHOis: [PET (Kerala) 2006]
'(a):O ." 0 (b) 2 0
iC'(c) 3 . 0 (d) 4 0 o
(e) 6 0
81. Atllong the following which one can have meso form?
(AIIMS 2006J 89. Which of the following molecules is expected to rotate the
(a) CH3CH(OH)CH(CI)C 2H s o plane of polarised light? [AIEEE 2007]
(b) CH3 CH(OH)CH(OH)CH3 o COOH CHO
(c) C2H5CH(OH)CH(OH)CH~ o (a) H2N I H 0 (b) HO I H 0
(d) HOCH 2CH(CI)CH 3 o H CH2 0H
82. Which of the following is not chiral? NH2~NH2
[CBSE (Med.) 2006] .(c)~ 0 (d) H~H 0
(a) 3-Bromopentane o SH Ph Ph
(b) 2-Hydroxy propanoic acid o 90. Which one of the following molecules has S-configuration?
(c) 2-Butanol o [PMT (Kerala) 2007]
(d) 2,3-Dibromopentane o COOH COOH
83. Consider the following representation,
CH3 CH 3 (a) HO-+Hi--CH3 D. (b) H-+I---OHD
CH2 COOH
H+Br F+H
F Br COOH CHO
they are: [PMT (Kerala) 2006] (c) HO' I Br 0 (d) HO+--CH 2 0H 0
(a) enantiomers., 0 CH 2COOH' H
(b) .diastereomcrs 0 COOH
.tc) conf9rmational isomers 0
(d) identical' 0 (e) CH 3-+-I--CH2 0H 0
. (e) cis-trans isomers 0 C6H 5
84. The term anomers of glucose refers to: [AIEEE 2006] 91. The major product fol'Il'le'd when a 3,3-dimethylbutan-2-01
(a) isomers of glucose that differ in configurations at is heated with concentrated sulphuric acid is:
carbonsoneand four (C-I andC-4) 0 . . [PMT (Kerala) 2007]
(b) a mixture of (D)-glucose and (L )-glucose 0 (a) 2,3-dimethyl-2-butene 0
(c) enantiomers of glucose 0 (b) 2,3-dimethyl-I-butene 0
(d) isomers of glucose that differ in configuration at carbon (c) 3,3-dimethyl-l-butene . 0
one (C-I) 0 (d) cis and trans isomers of2,3-dirnethyl-I-butene 0
85. Number of primary amines of the formula C 4H lI N is: (e) cis and trans isomers of 3,3-dirnethyl-2-butene 0
(BHU 2006] 92. The correct statement about the compounds I, II and III is:
. (a) I o (b) 2 o [PMT (Kerala) 2007]

~: H~H
(c) 3 o (d) 4 o

".~. ©H mW,~CHO = \
[AMU (Med.) 2006] \
:=f:COOCH
.. : .\
;

'COOH COOCH3
(I) (Ill)
(a) position isomers 0 . (b) chain isomers 0
(c) functionalisomers 0 (d) stereoisotners 0 (a) I and II are identical 0
87. Number of structural isomers for C6H 14, is: [lIT 2007] (b) I and II are diastereomers 0
(c) I and III areena:ntjOl~ers 0
(a) 3 0 (b) 4 0
- (c) 5 0 (d)'6 0 (d) I and II are enantiomers []
88. CH3-CHCI-CH 2 -CH3 has achiral centre. Which one (e) II .and III are enantiomers .0
93. Geometrical isomerism is.possible in: [JEE (WB)2007)
. of the following represents its R-configutation?
. [eBSE (Med.) 2007]
(a) isobutene 0 (b) acetone-oxime 0
(c) benzophenone-oxirne 0 (d) acetophenone-oxirne 0
Isomerism

94. Which of the following will have a meso-isomer also? 100. The total number of isomers in C6H3 Cl 3 is:
[UPSEE (Engg.) 2007; AFMC (Med.) 2007] [DPMT 2007]
(a) 2:3-Dichlorobutane 0 (a) two 0 (b) three o
(b) 2-Chlorobutane 0 (c) four 0 (d) five o
(c) 2,3-Dichloropentane 0 101. How many stereo isomers does this molecule have?
(d) 2':'Hydroxy propanoic acid 0 H 3 C-CH=CHCH2CHBrCH 3 [CBSE (Med.) 2008]
95. Which of the following molecules will not show optical (a) 2 0 (b) 4 0
activity? [PMT (Kerala) 2007] (c) 6 0 (d) 8 0
CH 102. The absolute configuration of the following:

7,
¥(, 3
CH 3
W '00 0
HO...,.... ,

H3 C
H Cl-i- H
H + . Cl,is:

C2 HS
[DCE(Engg.) 2008]

H 3 <J.;-CH-CD3 (a) 2S,3R 0 (b)2S,3S o

0 (d) 2R,3R o
~H
(c) 2R,3S
(b) 0 103. The absolute configuration of

(c)
COOH
H~~~
COOH
,
o H~:X7<::2H
HH
, is: [AIEEE 2008)

(a)S,R 0 (b)S,S 0
(c) R, R 0 (d) R, S 0
(d) B r A H o 104. C g H 16 that can form cis-trans geometrical isomers and also
H . Br
has a chiral centre, is: [AIIMS 2008]
(e) H3~-CH2-CH3 o
(a)~ 0 (b)~H 0
CI
96. Pick out the correct statements: [PMT (Kerala) 2007] (c) both of these 0 (d) none of these 0
(i) if a compound has no asymmetric carbon atom, it is 105. Which of the following is chiral? [DPMT 2008]
always achiral. (a) CICH2CH2CH2CH2CH3 0
(ii) if a compound has just one asymmetric carbon atom, it (b) CH3 CH2CHCH 2 CH3 " 0
is chiral. I
(iii) if a compound has more than one asymmetric carbon CI
atoms, it mayor may not be chiral. (c) CICH=CHCH 2 CH 2 CH 3 o
(a) (i), (ii) and (iii) are correct 0 (d) HC=C=CHCH 2 CH3 ,0
(b) (i) and (ii) only are correct 0 I
(c) (ii) and (iii) only are correct 0 CI
(d) only (ii) is correct 0 106. Of the isomeric hexanes, the isomers that give the minimum
(e) only (i) is correct .0 and maximum number of monochloro derivatives are
97. The chirality of the compound respectively: . [PET (Kerala) 2008)
(a) 2,3-dimethylbutane arid n-hexane 0
(b) 3-methylpentane and2,J-dimethylbutane 0
(c) 2,2':'dimethylbutane'and 2-methylpentane 0
(d) 2,3-dimethylbutane and 2-methylpentane 0
(e) 2-methylpentane and 2,2-dimethylbutane 0
IJIPMER (Moo.) 2007]
107. How many chiralcarbon atoms are present in
(a) R 0 (b) S 0 2,3,4-trichloropentane? [MGIMS (Wardba) 2008]
(c) Z 0 (d) E 0
(a) 1 0 (b) 2 0
98. Different structures generated due to reaction about C-C (c) 3 '0 (d) 4 0
axis of an organic molecule, are examples for:
108. The total number of acyclic isomers including the
ICET (J & K) 2007]
stereoisomers (geometrical and optical), with the molecular
(a) geometrical isomerism o formula, C~H7Cl is: IGGSIP (Engg.) 2008]
(b) optical isomerism o (a) 12 0 (b) II 0
(c) conformational isomerism o (c) 10 0 (d) 9 0
(d) structural isomerism , o 109. Which of the following will exhibit cis-trans isomerism?
99. The number of geometrical isomers in [JEE (WB) 2008]
[DPMT 2007]
CH3CH=CHCFhCH=CH2 is:
(a) two 0 (b) three o (a) CH2Br-CH2Br o (b) CBr3~3 0
(c) four 0 (d)five o (c) CHBr=CHBr o (d) CBt2 =CH2 0
 .... '
' ': .. ..
'
;', '.

110. Whichooo','Iof the follbwing ·compounds is capable ·of. List I' ListH'
..e.xistin~,~ameso form? . .,' (PET (Kerala)2008) o
. ,.·(a) ),~~Dlbromopentane 0 (b) 4-Bromo.:.2-pentanol 0 " . II ..
.·',(c) 3~BroQlo-:2-pentanol 0 (d) 2,3-Dibtomopentane [] (i) l. Apaiiofchainisomers:{1) CH3":--C-CH2CooC2H s;'
: (e) .2A~Dib!omopentaneD i " ',=i?' OH
J.

,HI. Which .6f the following comp6Unds will exhibit ds~trans

. I , I
CH 3-C=CHCOOC2H s
, (geometrical) isomerism? " , [CBSE (Meel.) 2009)
"\a)))utanol,D (b) 2-'Butyne '. 0 , 2.. A pair of position (B) CH3CH 2CH2CHO; CH 3COCH 2Cll3
.(<;) i':B.,utenol . o
(d) 2-Butene 0
3, A pair of functional . (C) CH 3CH2-C-CH;
til. The two structures written below represent:
isomers CH:r-Cl'EC-CH3,
.CH3. CH 2 0H
4. A pair of tautomers (D) CH 3CH 2CH2CH3; CH 3-CH-CH3
..,HO+.H H H
. I
.;H+OH OH CH 3

CH 2 0H Codes /;.a) I~A, 2-B, 3-C, 4-D, (b) I-D, 2~C, 3-B, 4-A
(c) l-B, 2-D, 3-A, 4-C, (d) I-C, 2-A, 3-D, 4-B
, {i}.:pair of diastereomers [JEE (WB) 2~) (ii) 1. A pair of optical
'.' ;'(b) pair of en~tiomers ,0 isomers
(c) same mol~cule [j
(d) both are optically inactive D
-~
.113. Which of the following compounds will show geometrical
. isomerism? [DPMT 2009)
(a) Cyclohexene 0
(b) 2-Hexene 0
. . (c) 3-Hexyne . 0
COOH
I. HOOf
(d) 1,I-Diphenyl ethylene D 2. A pair of geometrical (B) H-C""":OH ,H-r-OH
, 114.A C?mpound is formed by substitution of two chlorine, for
two hydrogens in propane. The nu.rtlber of possible isomeric
isomers 1
HO-f- H H-1- 0H

:(;)m~ounds is: 0 (b) 3 (JEE (WB) 20~1

COOS HOOC

,', ::(c)·4 ,0 (d) 5 .0 3. A pair of metamers (C) C2HsOC2Hs;CH3OC3H7

llS:The numbe.rof stereoisomers possible for a compound of CH 3 H 3C'
the molecular formula ,4. A pair of . . I.
(D) HO-C-H' R-C-OH
1
CH3 -CH=CH-CH(O~Me is : diastereomers
1 ' I
[AIEEE, 2009, ) COOH COOH.
(a) 2 0 (b) 3 0
(c) '4-. 0 (d) 6 D 'Cooes ta) I-D, 2-A, 3-C, 4"B, (b) I~A, 2-B, 3·0, 4-C
116.Which isomer of hexane has only two different sets. of , (c) I-C, 2-D; 3-B, 4-A, (d) I-B, 2-C, 3-A, 4-D
, structura:lly equivalent hydrogen atoms? [DPMT 2009) (iii) L Conformation (A) Polarimeter,
(a) 2;2-Dimethyl butane D (b) 2-Methyl pentane D', . 2. Meso form (B) Optically inactive
(c) 3-Methyl pentane 0 (d) 2,3-pimethyl butane D 3.~pecific rotation, (C) Eclipsed and staggered fonns
tt7.The ,total number of acyclic structural and optical isomers 4.Non-superimposable (D) Enantiomers
~ossible for a hydrocati;'Cln of the molecular formula HI6«7 mirror images
IS: , ' ,(CET (J&K)12009] Codes ta) I-A, 2-D, 3-B, +C, (b) I-D, 2-A, 3-C, 4-B
(a) 6 0 (b) 8 " \ D (c) I-B, 2-C, 3-D, 4-A, (d) I-C, 2-B, 3-A; 4-D
(c) 10 o (d) ,12 0 , CH3
Its.The alke.ne that..exhibitsgeometrical isomerism is: (iv) I. Apairofanomers (~)H+OH; HO H
. [AIEEE 2009) C;Hs HsCz
.,' ,. (a) propene o (b) 2-methyl propene. D
\. . (c) 2,.butene " o (d) 2-methyl-2-butene 0 w .
2. Enolisation (B) CH3"':""C-COOH; ,
.. SET. II: Thi,s set contains questions' with one or more oorrecitanswers:
(-)CH3-CH-COOH
. . 1l9~atch the list I and list II and select the correct answer using I ','
. :~~_~.~de given belqwthe lists: OH
W yH
3. Asymmetric synthesis (C) CH 3-C-CH 3; CH 3-C=CH2 ,
 'L

Isomerism

±:I H±HI
COOH

4, Fischer projection
I .....'
(D) HO-C-H 0 ' HO-C-H 0
! ~
(d)
<o8~> , '. []

~HI H~HI
COOH CQOH
127. Which of the following compounds will show' g~metricaJ
. I· 1 isomerism?"
H~ H--€
1 .1 (a) 2-Butene 0 (b) Propene .0'
CHzOH CH20H (c) I-Phenyl pr6pene 0 (d) 2-Methyl-2-butene 0
Codes :(a) I-C, 2-A,3-D, 4-B, (b) I-A, 2~B, 3-C,4-D

<)-CH~CH"--oH
128. Tautomerism is exhibited by:
(c)1-D,2-C, 3-B, 4-A, (d)l-B, H), 3-A:. 4-C
1l0~Cis-2-butene and trans~2-butene are : (a)
o
(a)· geometricalisom~rs P (b). diast(!reomers .;'; . . 0
o
(b},O~>=o o
(c) enantiomers. . ' . (d) position isomers 0

yo·
121. Whichoftbe foliowingcan.existin 'sYJ?' and 'anti; forms?
. (a)C6HS-,--N N:":':"OH' . . . "0-
- ':.. ',', - -\

(b) C6HS-N N~C6Hs 0 (e)

(c) C6HS-CH N-':':OH o
(d) (C6HshC N-OH o
122. The Z-isomer among the following 'are:
CH 3-:-C-:-H '.
. . . ~. ".
CH 3-:-C-H
'~. .
(d)QO . .0.

.
o
C3H 7-C::'....-C 2H s C2Hs-:-c-C3H7
129. Geometrical isomerism is exhibited by; . . . ....... .....
(I).. (II)
. [BHU (Mains) 2008] .
Cl-C-Br CI-:-c-Br (a) 2-chlorobut;'2-ene 0 (b) but-2.:.ene .. :,':.- ·tJ
I II' (c) 3~methylpent-2-ene 0 (d) 2-methYl but~2-ene·tl\
H-C-F F-C-H
130. The correct statement(s) about the compound given below"
(Ill) (IV) is ( a r e ) : ' . . .. (lIT 2008]
(a) (I) [] (b) (II) 0

'H.:~·
l'~
(c) ( I I I ) . 0 (d) (IV) 0
123. Keto-enol tautomerism is observed in:
.CH3
(a) C6Hs-CHO 0 (b) C 6H 5 COCH 3 0 . 3 '"~H .
(c) C6HsCOC6HS [J (d) C 6 H s COC1I2COCH3 b Cl
124. Which of the following statement(s) is/are. correct about· (a) the compound is optically active .
tautomers? (b) the compound possesses centre of s)'l:111i1etry
(a) They possess·different electronic aI\d atomic arrange- ( c) the compound possesses' planeof"synimetty
ments . 0 (d) the compound possesses axiS:-Qf synimetry
(b) They possess different .electronic but sa~e atomic 131. The correct statement(s) concemingthe sttfiCtures E,Fand
airangement ' 0 G is (are); . . - - ' \. .j ·.[nT2008]
(c) They have different atomic arrangements but same
electronic arrangement' [] H3C~O H3C~OH H3C:>==<CB.
(d) They exist in equilibrium \, .,' 0 H3C .CH3 H3C CH3 . H3C OH
125. The lowest molecular weight alkanes, which arc: optically (E) (1') -(0)
active, are:
(a) 3-methylhexane 0 (a) E, F and G are resonance stntctnres ·0
(b) 2,3-dimethylpentane 0 (b) E, F and E, G are tautomers , ','0
(c) 2,3,3-trimethylbutane
(d) 2-methylhexane
[J
0
(c) F and G are geometrical isomers
Q.
o
(d) F and G are diastereomei:s
126. Which of the following compounds are chiral and resolvable? 132. The correct statement(s) about the compound
+
(a) [C6HS N(CH2CH2CH3)(C2Hs)(CH3)]Br- 0 H 3C(HO)HC-CH=CH-CH(OH)CH3 (X)is(arel: .'
. .,lnT1009)
(b) C6 H 5 N(CH 3 )(C 2 H s ) 0 (a) the total number of stereoisomers possible for (X) is 6
(c) CH3CH2CH(CH3)N(CH3J(C2Hs) 0
 G.R.B. Organic 'Chemistry (Or Competitions

(b) the total number of diastereomers possible for (X) is 3 (d) if the stereochemistry about the double bond in (X) is
. ,0 .cis, the number of enantiomers possible for (X) is 2 0
(c) if the stereochemistry about the double bond in (X)' is "
trans, the number of enantiomers possible for (X) is 4 0

.ASSERTION-REASON TYPE QUESTIONS

Section A: liT Type Questions Sectlon.B: AIIMS Type Questions
The questions given below consist of an· Assertion (A) and Choose the correct answer:
Reason (R). Use the following keys to choose the correct (a) If both (A) and (R) are true and (R) is correct
answer: explanation of (A).
(a) If both assertion (A) and reason (R) are correct and (b) If both (A) and (R) are true but (R) is not correct
reason (R) is correct explanation of assertion (A). explanation of (A). .
(b) If both assertion (A) and reason (R) are. correct but (c) If (A)is true but (R)is false.
reason (R) is not correct explanation of assertion (A). (d) Ifboth (A) and (R) are false.
(c) If assertion (A) is correct but reason(R) is incorrect, 7. (A) Alkanes containing more than" three carbons exhibit
(d) If assertion (A)is incorrect but reason (R)is correct. chain isomerism.
(e) If both assertion (A) and reason (R)are incorrect. (R) All the carbon atoms in alkanes are sp3 -hybridized.
1. (A)Allcompounds having C=C bond exhibit geometrical 8. (A)Lactjc acid shows geometrical isomerism.
isomerism. (R) It has a C=C double bond.
(R) Rotation about C=C bond is restricted. 9. (A)Metamers can also be chain or position isomers :
2. (A)Diastereomers are not mirror image of each other. (R) The term tautomerism was introduced to explain the
(R)Diastereomers may be optically active. reactivity of a substance .according to two possible

H3)C~C-N<CH H3)C~C-N H
.' H . CH
3
<
3.. (A) Following amide exist in two StruCturlll forms:

3
structures.
10. (A)All the hydrogen atoms in but-2-ene lie in one plane.
(R) All the carbon atoms in it are sp2 -hybridized.
11. (A) Benzaldehyde forms two oximes on" reacting with
(1) (II) NH2 0H.
(R)The two oximes arise due to geometrical isomerism
(R) Rotation about carbon nitrogen bond is restricted due to around C N bond.
resonance.· 12. (A)Cyclobutane is less stable than cyclopentane.
4. (A)Dextro-isomers rotate the plane of .polarised light . (R) Presence of 'bent bonds' causes loss of orbital overlap.
towards right. .
13. (A) Ethyl acetoacetate gives reddish violet colour on
(R)Dextro-isomers are represented by putting (D) before treatment with ferric chloride.
their name. (R) 'Keto' form is dominant in it.
5. (A)Trans-l-chloropropene has higher dipole moment than 14. (A) The boiling point 6f cis-l,2-dichloroethene is higher
.cis- t -chloropropene.
than corresponding trans-isomer.
(R)The resultant of the two vectors in trans-l-chloro (R)The d~pole moment of cis-l,2-dichloroethene is higher
. propene is more than injis-l-chloropropene. than trans-isomers.
6. (A)Meso tartaric acid i~ptically inactive. 15. (A) Molecules that are not superimposable on their mirror
(R)Meso tartaric a>i«has plane of symmetry. images are chiral. (lIT 2007]
(R) All chiral molecules have chiralcentre.·
Isomerism 161-

_J ANSWERS I
OBJECTIVE QUESTIONS
-.
1. (e) 2. (e) 3. (b) 4. (d) 5. (a) 6.· (d) 7. (b) . 8. (d) 9. (e) 10. (b)
11. (b) 12. (a) 13. (a) 14. (e) 15. (c) 16. -(c) 17. (d) 18. (a)· 19. (e) 20. (c) .
21. (a) 22. (e) 23. (a) 24. (e) 25. (d) 26•. (d) 27. (d) 28. (d) 29. (b) 30. (a)
31. (a) 32. (d) 33. (b) 34. (b) 35. (c) 36. (c) 37. (c) 38. (d) 39. (b) 40. (a)
41. (b) 42. (d) 43. (a) 44. (c) 45. (al. 46. (d) 47. (b) 48. (a) 49. (d) 50. (a)
51. (c) 52. (b) . 53. (a) 54. (c) 55. (d)'. 56. (b) 57. (a) 58. (b) 59. (d) 60. (a)
61. (b) 62. (a) 63. (c) 64. (c) 65. (b) 66. (b) 67. (b) 68. (b) 69. (b) 70. (d)
71. (b) 72. (e) 73. (a) 74. (e) 75. (e) 76. (d) 77. (a) 78. (c) 79. (c) 80. (d)
81. (b) 82. (a) 83. (d) 84. (d) 85. (d) 86. (c) 87. (c) 88. (b) 89. (b) 90. (e)
-91. (a) 92. (a) 93. (d) 94. (a) 95. (a) 96. (c) 97. (a) 98. (c) 99. (a) 100. (b)
101. (b) 102. (b) 103. (c) 104. (a) 105. (d) 106. (d) 107. (b) 108. (a) 109. (c) 110. (e)
111. (d) 112. (c)- 113. (b) 114. (d) 115. (c) 116. (d) 117. (b) 118. (c)
119. (i-b), (ii-a), (iii-il), (iv--c) 120. (a,b) 121. (a,b,c) 122. (a,c) 123. (b,d) 124. (a,d) 125. (a,b) 126. (a,c)
127. (a,c) 128. (a,e,d) 129. (a,b,e) 130. (a,d) 131. (b,c,d) 132. (a,d)

ASSERnON-REASON TYPE QUESnONS

1. (d) 2. (c) 3. (a) 4. (c) 5. (a) 6. (a) 7. (e) 8. (e) 9. (b) 10. (d)
11. (a) 12. (a) 13. (b) 14. (a) 15. (e) ,

..